The "Big" Picture
According to the Centers for Disease Control (CDC), the estimated annual medical cost of obesity in the U.S. was $147 billion in 2008 and the medical costs for people who are obese were $1,429 higher than those of normal weight.
For adults, overweight and obesity ranges are determined by using weight and height to calculate a number the "body mass index" (BMI). BMI is used because, for most people, it correlates with the individual's amount of body fat. It is important to remember that although BMI correlates with the amount of body fat, BMI does not directly measure body fat. A person is generally considered overweight if he or she has a BMI between 25 and 29.9 kg/m2. Obesity is defined as a BMI of 30 or higher.
Morbid (severe) obesity has been defined as:
- When a person's BMI is 40.0
- If a person has a BMI of 35-39.9 with at least one comorbidity related to obesity such as diabetes, heart disease, or sleep apnea
A Coding Perspective
Obesity code are located in the Endocrine, Nutritional and Metabolic Diseases chapter. Per ICD-10 Coding Guidelines, a diagnosis of a clinical condition (i.e. overweight, obese, severely obese, and morbidly obese) must be obtained from physical documentation. However, the BMI itself may be coded from the dietician and/or other caregiver supplied documentation.
Documentation to support a diagnosis of any clinical condition including morbid obesity, obesity, and overweight should also be supplied by the physician. Supporting documentation may include:
- Diet discussed
- Exercise encouraged
- Gastric bypass surgery consult
- Diet medication
- Dietician referral and/or counseling
- Weight loss program (i.e. gym membership)
- Food log
- Physiatrist referral
Accurately reporting BMI goes beyond documentation and coding. The Centers for Medicare and Medicaid Services (CMS) has identified BMI as a core quality measure of the Five Star Quality Rating System for Medicare Advantage (MA) Plans.
CMS uses data from surveys, empirical observation, administrative (claims) data, and medical records to collect specific elements such as BMI to measure the quality of the health plan. Each plan receives and overall star rating on a scale of 1-5. Star ratings are used to determine bonus payments that must be used to improve the quality of benefits and services to the members.
For more information on assessing BMI, obesity, and obtaining a healthy weight please visit the National Institutes of Health website at: